In recent years, as a standard for a recordable disc type recording medium that is detachable from a recording and reproducing apparatus, a blu-ray disc standard has been proposed. The blu-ray disc standard prescribes a disc that has a recording medium having a diameter of 12 cm and a cover layer having a thickness of 0.1 mm. The blu-ray disc standard uses a bluish-purple laser having a wavelength of 405 nm and an objective lens having a numerical aperture of 0.85. The blu-ray disc standard accomplishes a recording capacity of 27 GB (Giga bytes) maximum. As a result, a program of a BS digital high-vision broadcast available in Japan can be recorded for two hours or longer without deterioration of picture quality.
As sources (supply sources) of AV (Audio/Video) signals recorded on the recordable optical disc, an analog signal of for example a conventional analog television broadcast and a digital signal of for example a digital television broadcast such as a BS digital broadcast will be used. The blu-ray disc standard has established a method for recording AV signals of such broadcasts.
As a derivative standard of the current blu-ray disc standard, a reproduction-only recording medium on which a movie, music, or the like is prerecorded is being developed. As a disc-shaped recording medium on which a movie or music is prerecorded, DVD (Digital Versatile Disc) has been widely used. The reproduction-only optical disc in accordance with the blu-ray disc standard is largely different from and superior to the conventional DVD in a large recording capacity and a high speed transfer speed that allow a high-vision picture to be recoded for two hours or longer in high quality.
The current blu-ray disc standard prescribes neither a method for displaying a list of video contents of a disc on a screen nor a user interface function for allowing a user to move a cursor on the list and select a video content that he or she wants to reproduce from the list. These functions are accomplished by a recording and reproducing apparatus main unit that records and reproduces video contents to and from the blu-ray disc. Thus, even if a video content is reproduced from the same recording medium, the layout of the contents list screen depends on the recording and reproducing apparatus for use, and so does the user interface. Thus, the user cannot easily use the blu-ray disc. Thus, it is necessary to allow the reproduction-only disc to display a menu screen and so forth that the disc (contents) producer has designed, not depend on the reproducing apparatus.
A multiple story function of which a selection screen is displayed while a video content is being reproduced is generally called an interactive function. To accomplish the interactive function, it is necessary for the disc producer to create a scenario that he or she has designated a reproduction order and branches of the video content, describe the scenario using a program language, a script language, or the like, and record the described scenario on a disc. The reproducing apparatus side reads and executes the scenario. As a result, the reproducing apparatus reproduces a video content and displays selection screens that allow the user to select branches of the video content that the producer has designated.
The current blu-ray disc standard (blu-ray disc rewritable format ver 1.0) prescribes neither a method for composing a menu screen and a branch selection screen that a contents producer has designated, nor a method for describing a process for a user input. Currently, it is difficult to reproduce a video content from a blu-ray disc in accordance with a scenario that the producer has designated with compatibility irrespective of manufactures and models of reproducing apparatuses.
For a reproduction-only disc, the producer side desires a multiple angle function for allowing a user to select one of angles of an object photographed by a plurality of cameras so that the user can watch the object at his or her favorite angle. Thus, it is necessary to provide such a function.
For a reproduction-only disc, a function for displaying subtitles is essential. However, the current blu-ray disc standard does not prescribe the function for describing subtitles.
The foregoing interactive function has been already accomplished in for example the DVD (Digital Versatile Disc) standard. In the DVD video, while a moving picture is being reproduced, a menu screen is called using for example a remote control commander. By selecting a button displayed on a menu screen, the user can perform a process for changing the current scene that is being reproduced. The DVD standard also prescribes a function for displaying subtitles. That function allows the user to switch Japanese subtitles to English subtitles or vice versa that have been prepared. In addition, the DVD video also has a multiple angle function.
In the case of the DVD, a menu screen is composed of a fixed sub picture. When the menu screen is called, it is displayed in such a manner that the sub picture is combined with a moving picture. Japanese Patent Laid-Open Publication No. HEI 10-308924 describes a structure for combining sub picture data with moving picture data and recording the combined data on a recordable DVD.
Next, an example of a menu screen according to the related art reference will be described in brief. Before a movie main part is reproduced from a DVD by a reproducing apparatus, a menu screen is displayed. Generally, a plurality of buttons are disposed on the menu screen. Each button is assigned a predetermined operation. When the user selects a button and causes the operation of the selected button to be executed, the operation assigned to the selected button is executed. When the user selects a button “movie main part” and causes the operation of the selected button to be executed, the operation assigned to the button is executed. As a result, the movie main part is reproduced from the DVD.
The user operates keys (direction keys) assigned to up, down, left, and right directions with the remote control commander (hereinafter referred to as remote controller) so as to select one button displayed on the menu screen. Thereafter, with an OK key, the user causes the operation assigned to the selected button to be executed. Each button has three states that are a normal state (non-selection state), a selection state, and an execution state. To allow the user to easily distinguish them, they have different images and colors. Generally, there is only one button that is placed in the selection state or the execution state.
In the DVD video, each button is displayed with two types of data called sub picture and highlight. FIG. 1 shows an example of a DVD menu screen 300 according to a related art reference. The menu screen 300 is referred to as “title menu”. The menu screen 300 has three buttons 301A, 301B, and 301C that represent “move main part play”, “bonus picture”, and “sound setting”, respectively. In the example shown in FIG. 1, the color of an outer frame of the “movie main part play” button 301A has been changed from the original color. That describes that the “movie main part play” button 301A has been placed in the selection state.
In such a state, when the user operates the direction keys on the remote controller, for example as shown in FIG. 2A, FIG. 2B, and FIG. 2C, he or she can causes another button to be placed in the selection state. Like the case shown in FIG. 1, the color of the outer frame of the button that has been selected is different from the colors of the outer frames of the other buttons that have not been selected (non-selected buttons). In the state shown in FIG. 1, when the user operates an OK button disposed on the remote controller, as shown in FIG. 3, the color of the “movie main part play” button 301A is changed to a color that represents the execution state. Thereafter, the menu screen 300 is cleared and the movie main part is reproduced. The foregoing is a basic operation of buttons of the DVD video.
The menu screen 300 as shown in FIG. 1 is composed of three types of data that are a background picture 310, a sub picture 311, and a highlight 312. The background picture 310 is a still picture, a moving picture of a content main part prerecorded on the DVD, or the like.
As shown in FIG. 5, the sub picture 311 has one bit map picture, four color information (A0, B0, C0, and D0), and coordinates (X, Y). The bit map picture is represented with information of two bits per pixel. The coordinates (X, Y) represent the display start position of the sub picture 311. Each of the color information A0, B0, C0, and D0 is one-color information data composed of one set of R (Red), G (Green), and B (Blue) data. Each of colors R, G, and B has information of eight bits. The bit map picture has information of two bits per pixel. With two bits, one is selected from the foregoing four-color information (A0, B0, C0, D0) for each pixel. Color information also has transparency data. The sub picture 311 may have a region in which the background picture 310 is transparent. The display position of the upper left corner of the sub picture 311 is represented with coordinates (X, Y) relative to the background picture 310.
The sub picture 311 may have information that represents a display start time and a display end time and commands that cause visual effects such as fade-in and fade-out to be applied to the sub picture 311.
In the DVD video, a plurality of bit map pictures cannot be displayed at the same time. Thus, the menu screen 300 on which the plurality of buttons as shown in FIG. 1 are placed is displayed with one large bit map picture that has three button images as shown in FIG. 4B. In the bit map picture of the sub picture 311 shown in FIG. 4B, when a region outside the buttons 301A, 301B, and 301C is designated as a transparent region and the sub picture 311 is combined with the background picture 310, the background picture 310 becomes transparent outside the display regions of the buttons 301A, 301B, and 301C.
The highlight 312 is information used to change four colors used for the sub picture 311 to other four colors. As shown in FIG. 5, as color information, the highlight 312 has color information (A1, B1, C1, D1) of a selection state and color information (A2, B2, C2, D2) of an execution state. These color information is four-color information represented with RGB of eight bits each like the foregoing sub picture 311.
The highlight 312 has a set of coordinates of regions in which colors are changed. The range of which colors are changed is not limited to all the sub picture 311, but a part of the sub picture 311 as a square region. The number of square regions in the sub picture 311 of which colors are changed by the highlight 312 corresponds to the number of buttons that the user can select. The display position of each square region is represented by coordinates (X, Y) of the positions of the upper left corner and the lower left corner thereof. For example, the position of the highlight 312A corresponding to the button 301A is represented by coordinates (X1, Y1) and (X1′, Y1′). That applies to the highlights 312B and 312C corresponding to the buttons 301B and 301C, respectively.
For example, in the highlight 312A, color information (A0, B0, C0, D0) of a region represented by coordinates (X1, Y1) and (X1′, Y1′) of the background picture 310 is changed to color information (A1, B1, C1, D1) designated as a color of a selection state. At that point, the color information A0 of the background picture 310 is changed to color information A1 of the highlight 312A. Likewise, the color information B0 of the background picture 310 is changed to the color information B1. The color information C0 is changed to the color information C1. The color information D0 is changed to the color information D1.
Next, an example of a color change of the highlight 312 will be described corresponding to a change of a state of the button 301A on the menu screen 300 described with reference to FIG. 1, FIG. 2A, FIG. 2B, FIG. 2C, and FIG. 3. It is assumed that when the button 301A is in the non-selection state, the frame, front surface, and characters of the button 301A are displayed with the color information B0, the color information C0, and the color information D0, respectively. When the button 301A is placed in the selection state, the frame color B0 of the button 301A is changed to the color information B1 corresponding to the selection state of the highlight 312A. At that point, the front surface color C0 and the character color D0 are not changed. Thereafter, when the button 301A is placed in the execution state, the front surface color C0 of the button 301A, which is the color of the selection state, is changed to the color information C1. At that point, the frame color B1 and the character color D0, which are the colors of the selection state, are not changed.
When a picture of the DVD video is normally reproduced, a picture corresponding to the background picture 310 is displayed. When a movie that has subtitles is reproduced, the background picture 310 of which the movie main part is reproduced and the sub picture 311 of which the subtitles are displayed are combined and displayed.
However, the sub picture 311, the highlight 312 that represents the selection state, and the highlight 312 that represents the execution state can use only up to four colors each. Thus, as a problem of the related art, a sub picture having many colors cannot be displayed.
Since the highlight 312 only changes the color of the sub picture 311, characters of a button cannot be changed in the selection state and the execution state. In addition, an effect of which the shape of a button is changed cannot be accomplished. Thus, the related art cannot accomplish an enriched user interface.
Since subtitles and buttons are displayed using the same mechanism using the sub picture 311, the subtitles and the buttons cannot be independently controlled and displayed. In addition, a combining process for setting and combining transparencies of the subtitles and buttons and displaying the combined picture cannot be performed.
When the menu screen is called, moving picture data reproduced in the background thereof is stopped. Thus, even if such an interactive function were accomplished, the flexibility of the user interface that accomplishes the function would be low.
Since a mechanism for generating an effect sound in synchronization with subtitles displayed and changed has not been prescribed in the standard, an effect sound cannot be generated in synchronization with subtitles as a problem of the related art.
Since the standard does not prescribe a mechanism for generating effect sounds for buttons such as an effect sound that is generated when the user places a button in the selection state and a click sound that is generated when the user operates an OK key in the selection state of a button. Thus, it is difficult to accomplish an enriched user interface as a problem of the related art.
When a user interface having high flexibility is accomplished, it is largely affected by the drawing speed and update speed of buttons and the responsiveness to an input of the user. Thus, a graphic decoder model that estimates them is required.
In the foregoing, the effect sound is not sound data that is reproduced in synchronization with a moving picture or a still picture displayed on the moving picture plane (for example, sound that is recoded as a pair of a movie picture), but audio data reproduced in synchronization with a display control of subtitles and buttons.